1. Technical Field of the Invention
The invention relates to elevator dispatching and, more particularly, to improvements in estimating remaining response time (RRT) to answer a hall call.
2. Discussion of Related Art
Remaining response time (RRT) is the amount of time that a given elevator will require to reach a given hall call floor. For example, a car in the down direction and parked at floor 9 might require 6.0 seconds to respond to a newly registered down hall call on floor 7; in that case it is said that the RRT equals 6.0 seconds. The RRT for another car presently on floor 16 would be much longer. Another important illustration of RRT is the case where a car is in the process of responding to a hall call that has already been waiting for some time. Here, the RRT is the time from now until the car arrives at the hall call floor. The RRT is a key concept in dispatching decisions.
Co-owned U.S. patents pertaining to RRT include, among others, U.S. Pat. Nos. 5,146,053; 5,388,668; 5,427,206; and 5,672,853. Clearly, accuracy of an estimation procedure for RRT is critical, especially as it is applied to dispatchers with ECA (Early Car Announcement: See U.S. Pat. No. 5,338,904). If the destination of each waiting passenger were known, a more accurate prediction of RRT would be possible.